The present invention relates to digital cordless telephone systems and sets and, more particularly, to a method of and a system for recognizing high speed movement of a digital cordless telephone set.
Prior art digital cordless telephone sets have been incapable of checking by themselves whether they are in high speed movement. Without capability of checking whether or not in high speed movement, it has been often the case that a measure against the occurrence of disability of communication due to the high speed movement is given up. Therefore, with a prior art digital cordless telephone set, for example, before driving a car the user himself or herself should make a prearrangement for prohibiting a termination call during driving the car. Also, in a train a great termination call sound may be generated to bother nearby people.
An object of the present invention is to provide a digital cordless telephone set and system capable of recognizing its high speed movement.
According to a first aspect of the present invention, there is provided a method of recognizing high speed movement of a digital cordless telephone set comprising:
a step of setting a reference speed of the digital cordless telephone set for high speed movement judgment; a step of setting a threshold of the variation cycle period of the received electric field level of the digital cordless telephone set corresponding to the reference speed for the high speed movement judgment; a step of measuring the variation cycle period of the received electric field level of the digital cordless telephone set in a predetermined time; and a step of recognizing that the digital cordless telephone set is in high seed movement when the measured variation cycle period of the received electric field level of the digital cordless telephone set becomes shorter than the threshold variation cycle period.
The step of setting the threshold of the variation cycle period of the received electric field level of the digital cordless telephone set corresponding to the reference speed of the high speed movement judgment includes: a step of measuring an average received electric field level of the digital cordless telephone set in a predetermined time; a step of counting number of times the received electric field level exceeds the average level as a threshold level in the predetermined time; and a step of computing number of times of exceeding the threshold in the predetermined time corresponding to the reference speed for the high speed movement judgment as a threshold number of times of exceeding the threshold for the high speed movement judgment; the step of measuring the variation cycle period of the received electric field level of the digital cordless telephone set is a step of counting the number of times the received electric field level exceeds the threshold level in the predetermined time periodically during movement; and the step of recognizing that the digital cordless telephone set is in high speed movement when the variation cycle period of the received electric field level of the digital cordless telephone set becomes shorter than the threshold variation cycle period is a step of recognizing that the digital cordless telephone set is in high speed movement when the exceeding times number count exceeds the threshold times number for the high speed movement judgment.
According another aspect of the present invention, there is provided a digital cordless telephone set comprising: means for setting a reference speed of the digital cordless telephone set for high speed movement judgment; means for setting a threshold of the variation cycle period of the received electric field level of the digital cordless telephone set corresponding to the reference speed for the high speed movement judgment; means for measuring the variation cycle period of the received electric field level of the digital cordless telephone set in a predetermined time; and means for recognizing that the digital cordless telephone set is in high seed movement when the measured variation cycle period of the received electric field level of the digital cordless telephone set becomes shorter than the threshold variation cycle period.
The means for setting the threshold of the variation cycle period of the received electric field level of the digital cordless telephone set corresponding to the reference speed of the high speed movement judgment includes: means for measuring an average received electric field level of the digital cordless telephone set in a predetermined time; means for counting number of times the received electric field level exceeds the average level as a threshold level in the predetermined time; and means for computing number of times of exceeding the threshold in the predetermined time corresponding to the reference speed for the high speed movement judgment as a threshold number of times of exceeding the threshold for the high speed movement judgment; means for measuring the variation cycle period of the received electric field level of the digital cordless telephone set is a step of counting the number of times the received electric field level exceeds the threshold level in the predetermined time periodically during movement; and means for recognizing that the digital cordless telephone set is in high speed movement when the variation cycle period of the received electric field level of the digital cordless telephone set becomes shorter than the threshold variation cycle period is a step of recognizing that the digital cordless telephone set is in high speed movement when the exceeding times number count exceeds the threshold times number for the high speed movement judgment.
The high speed movement recognition system of the digital cordless telephone set includes an independent switch for starting the operation in response to the switching-on of a manual switch and stopping the operation in response to the switching-off of the manual switch.
The digital cordless telephone set further comprises means for automatically notifying the recognition of the high speed movement of the digital cordless telephone set to the person carrying the digital cordless telephone set.
According other aspect of the present invention, there is provided a mobile apparatus receiving radio wave transmitted from a plurality of radio wave transmission apparatuses which are located at a predetermined distance or distances, comprising: measuring circuit for measuring variation cycle period of strength of the received radio wave; and judging circuit for judging high speed movement state of the mobile apparatus when the variation cycle period of strength of the received radio wave is shorter than a threshold value determined based on the predetermined distance or distances.
The threshold value is determined on the basis of an average received radio wave strength in a predetermined time period. The threshold value is determined by adding a predetermined value to the average received radio wave strength.
According still other aspect of the present invention, there is provided a mobile apparatus receiving radio wave transmitted from a plurality of radio wave transmission apparatuses which are located at a predetermined distance or distances, comprising: measuring circuit for measuring strength of the received radio wave; counting circuit for counting number of times the measure strength is higher than a predetermined value; and judging circuit for judging high speed movement state of the mobile apparatus when the counted number is higher than a predetermined number.
According further aspect of the present invention, there is provided a judging method of high speed moving state of a mobile apparatus which receiving radio wave transmitted from a plurality of radio wave transmission apparatuses which are located at a predetermined distance or distances, comprising: measuring step for measuring variation cycle period of strength of the received radio wave; and judging step for judging high speed movement state of the mobile apparatus when the variation cycle period of strength of the received radio wave is shorter than a threshold value determined based on the predetermined distance or distances.
According to still further aspect of the present invention, there is provided a judging method of high speed moving state of a mobile apparatus which receiving radio wave transmitted from a plurality of radio wave transmission apparatuses which are located at a predetermined distance or distances, comprising: measuring step for measuring strength of the received radio wave; counting step for counting number of times the measure strength is higher than a predetermined value; and judging step for judging high speed movement state of the mobile apparatus when the counted number is higher than a predetermined number